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How do I print the type of a variable in Rust?
...r
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= note: expected type `()`
found type `{float}`
Or call an invalid method:
let mut my_number = 32.90;
my_number.what_is_this();
error[E0599]: no method named `what_is_this` found for type `{float}` in the current scope
--> src/main.rs:3:15
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3 | my_number.what_is_...
OpenCV C++/Obj-C: Detecting a sheet of paper / Square Detection
...e I was unable to find a relevant implementation I decided to accept the challenge.
I made some modifications to the squares demo present in OpenCV and the resulting C++ code below is able to detect a sheet of paper in the image:
void find_squares(Mat& image, vector<vector<Point> >...
What does mysql error 1025 (HY000): Error on rename of './foo' (errorno: 150) mean?
...
You usually get this error if your tables use the InnoDB engine. In that case you would have to drop the foreign key, and then do the alter table and drop the column.
But the tricky part is that you can't drop the foreign key using...
Why is pow(a, d, n) so much faster than a**d % n?
...was taking so long (> 20 seconds) for midsize numbers (~7 digits). I eventually found the following line of code to be the source of the problem:
...
querySelector and querySelectorAll vs getElementsByClassName and getElementById in JavaScript
...w what exactly is the difference between querySelector and querySelectorAll against getElementsByClassName and getElementById ?
...
Creating a simple XML file using python
...ee tutorial. (With example code for loading the best available option from all major ElementTree implementations)
As a final note, either cElementTree or LXML should be fast enough for all your needs (both are optimized C code), but in the event you're in a situation where you need to squeeze out ...
Changing selection in a select with the Chosen plugin
...
From the "Updating Chosen Dynamically" section in the docs: You need to trigger the 'chosen:updated' event on the field
$(document).ready(function() {
$('select').chosen();
$('button').click(function() {
$('select').val(2);
$('sel...
Undoing a 'git push'
... highly dangerous if you are working in a shared repo. As a best practice, all commits pushed to a remote repo that is shared should be considered 'immutable'. Use 'git revert' instead: kernel.org/pub/software/scm/git/docs/…
– Saboosh
Jan 13 '12 at 20:47
...
Python: What OS am I running on?
...ion of Darwin that comes with Catalina 10.15.2: en.wikipedia.org/wiki/MacOS_Catalina#Release_history
– philshem
Aug 21 at 13:28
add a comment
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check if variable is dataframe
...rame
Yes: isinstance(x, pd.DataFrame)
And don't even think about
if obj.__class__.__name__ = 'DataFrame':
expect_problems_some_day()
isinstance handles inheritance (see What are the differences between type() and isinstance()?). For example, it will tell you if a variable is a string (eithe...